One thing for sure, this is the same as receiving a gift of 2M U$D. Hunter should have to pay the IRS taxes on this... and he is on the hook for a quarterly payment in June to keep from having to pay interest on his $2M U$D Gift. At least anyone else would be paying interest on such a gift if they waited until 2023 to file this year’s taxes.
It is the giver that pays any tax due.